1. Field of the Invention
The present invention concerns a process and a device for washing and sterilizing plants for filling vials and similar containers, and particularly plants for filling pharmaceutical vials.
2. Description of the Prior Art
Such plants essentially comprise, besides a (trailer-mounted or fixed) container for the liquid to be metered, a pumping system consisting of one or more syringes, one or more corresponding filling nozzles to fill the vials, and one or more nozzles to inject nitrogen into each vial before its filling with the product in order to avoid oxidation of the product.
Chiefly in the case of plants handling medicinal products, it is necessary to perform washing and sterilization of the plant before each operation cycle, namely when the type of product treated is changed, or, for example, at the beginning of the day, when the filling plant, off since the previous evening, is started again.
In any case, sterilization must be performed immediately before the plant use, because, if time passes between sterilization and use, the plant can be contaminated again. Furthermore, it is current practice to perform a washing operation at the end of the operating cycle in order to avoid the products remaining in the plant from crystallizing or hardening, thereby clogging the plant in some points; the operations of cleaning-sterilization are thus doubled.
It is obvious that this represents a considerable disadvantage in that the number of working hours of the plant during the day is reduced by the time necessary for its sterilization.